Selenite
Selenite is one of the three forms of pure natural crystalline gypsum, with one other, satin spar having a very similar features, the other natural form is gypsum rock which is commonly crushed and used in the manufacture of plaster products.
In old English gypsum was referred to as spear stone (spærstn) because of its crystal spear-like projections, of which selenite and satin spar have the most notable. Selenite crystals are much rarer than satin spar crystals, whilst gypsum rock is relatively common. Other forms of crystalline gypsum are known as tabular gypsum, which is normally shorter blocks of satin spar, whilst desert roses, form with grains of sand and gypsum flower which are referred to as crystal habits.
Selenite crystals form in large flat, transparent crystals, often called plates or windows, whilst Satin Spar crystals are fibrous and white, often appear as raw rulers or wands which can be polished into palmstones or spheres. The naturally large flat transparent form of selenite crystals, might also be called Lapis Specularis a form of selenite that was put to good use by the Romans in the construction of specularia (sometimes referred to as specularium), which included the first types of windows before the development of glass for use in glazing, it was used to construct Roman winter gardens for horticulture.
[edit] Related articles on Designing Buildings
- Botanical gardens
- Construction materials.
- Conservatory.
- Drywall construction.
- Garden greenhouse.
- Gypsum.
- Hydroponics and buildings.
- Lime plaster.
- Minerals of local and national importance.
- Mortar.
- Permission for mining or working of minerals.
- Plaster.
- Specularium.
- The secret life of the Georgian garden.
- Types of glass.
- Winter gardens.
Featured articles and news
Boiler Upgrade Scheme and certifications consultation
Summary of government consultation, closing 11 June 2025.
Deputy editor of AT, Tim Fraser, discusses the newly formed society with its current chair, Chris Halligan MCIAT.
Barratt Lo-E passivhaus standard homes planned enmasse
With an initial 728 Lo-E homes across two sites and many more planned for the future.
Government urged to uphold Warm Homes commitment
ECA and industry bodies write to Government concerning its 13.2 billion Warm Homes manifesto commitment.
From project managers to rising stars, sustainability pioneers and more.
Places of Worship in Britain and Ireland, 1929-1990. Book review.
The emancipation of women in art.
Call for independent National Grenfell oversight mechanism
MHCLG share findings of Building Safety Inquiry in letter to Secretary of State and Minister for Building Safety.
The Architectural Technology Awards
AT Awards now open for this the sixth decade of CIAT.
50th Golden anniversary ECA Edmundson awards
Deadline for submissions Friday 30 May 2025.
The benefits of precast, off-site foundation systems
Top ten benefits of this notable innovation.
Encouraging individuals to take action saving water at home, work, and in their communities.
Takes a community to support mental health and wellbeing
The why of becoming a Mental Health Instructor explained.
Mental health awareness week 13-18 May
The theme is communities, they can provide a sense of belonging, safety, support in hard times, and a sense purpose.
Mental health support on the rise but workers still struggling
CIOB Understanding Mental Health in the Built Environment 2025 shows.
Design and construction material libraries
Material, sample, product or detail libraries a key component of any architectural design practice.